1. Field of the Invention
The present invention relates to a headlight for a motorcycle suitably designed for increasing the brightness.
2. Description of Background Art
A conventional headlight for a motorcycle is known, for example, from Japanese Patent Laid-open No. 4-92731 entitled xe2x80x9cHeadlight Unit for Motorcycle.xe2x80x9d
FIG. 2 of this publication shows a headlight unit 10 including a lamp 13 for high beam and a projector lamp 14 for low beam laterally arranged close to each other on the opposite sides with respect to the longitudinally extending center line of a vehicle body. The lamp 13 includes a parabolic reflecting mirror 15a and a halogen bulb 16, and the projector lamp 14 includes an elliptic reflecting mirror 19a and a halogen bulb 20.
It is considered that the brightness of the headlight unit 10 can be improved, for example, by increasing the area of the parabolic reflecting mirror 15a of the lamp 13 or the elliptic reflecting mirror 19a of the projector lamp 14.
However, an increase in the reflection area of the parabolic reflecting mirror 15a or the elliptic reflecting mirror 19a results in an increase in the area of the front surface of the headlight unit 10, causing an increase in air resistance during running.
As another method for improving the brightness of the headlight unit 10, it is considered to increase the rated power of the halogen bulb 16 or 20. However, an increase in the rated power causes an increase in power consumption, so that it is necessary to increase the capacity of a power supply system for supplying power to the headlight unit 10, causing a cost increase.
Further, since the lamp 13 for the high beam and the projector lamp 14 for the low beam are arranged laterally on the opposite sides with respect to the longitudinally extending center line of the vehicle body, there occurs a problem in the cornering of the motorcycle. That is, when the vehicle body is inclined in the cornering of the motorcycle, the height of the lamp 13 from a road surface in the case of cornering to the left is different from that in the case of cornering to the right, causing a difference in illumination condition on the road surface by the lamp 13 between these cases. This problem occurs also on the projector lamp 14.
It is accordingly an object of the present invention to provide a headlight for a motorcycle which can increase the brightness without changing the rated power as maintaining aerodynamic characteristics and can illuminate the road surface under substantially the same condition both in the case of cornering to the left and in the case of cornering to the right.
In accordance with the present invention, there is provided a headlight arranged at a front portion of a vehicle body of a motorcycle, comprising a low-beam lamp arranged on a longitudinally extending center line of said vehicle body and left and right high-beam lamps arranged on the opposite sides of said low-beam lamp as viewed in plan.
The low-beam lamp arranged on the longitudinally extending center line of the vehicle body is turned on when meeting another vehicle, whereas the left and right high-beam lamps are turned on no traffic is approaching.
Since the left and right high-beam lamps are arranged on the opposite sides of the low-beam lamp, the total reflection area of reflecting mirrors of the left and right high-beam lamps can be increased. Preferably, the lens of the low-beam lamp and the left and right high-beam lamps is integrally formed and largely curved toward the front side of the vehicle body, so that the shape of the lens can be made nearly streamlined. Accordingly, although the area of the front surface of the headlight is large, an increase in the air resistance can be suppressed.
As a result, the brightness of the headlight can be increased without changing the rated powers of the bulbs of the low-beam lamp and the high-beam lamps.
Additionally, by symmetrically arranging the left and right high-beam lamps with respect to the low-beam lamp so as to be equally spaced therefrom, the illumination condition on the road surface by the high beam in the case of cornering to the left with the vehicle body inclined to the left can be made similar to that in the case of cornering to the right with the vehicle body inclined to the right.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.